A VIOLENT criminal who broke out of jail could be thrown back behind bars in Grafton, but only if he remains on the run for a few years.

Labor MP Guy Zangari asked during Question Time where John Robert Bamblett would be locked up once caught.

"Given that the prisons are now full, if he is ever recaptured, which prison will the minister put him in?" he asked.

The 35-year-old has been on the run for a week after escaping from a transport van in central NSW while being transferred to another jail.

He was one of eight NSW jail-breakers over the past year, six of whom have been recaptured.

Corrections Minister David Elliott said authorities would find space for him once he was tracked down.

"Beds are available in Long Bay. Cells are available. Cells will be available in Grafton," he said.

"There are more than 12,100 prisoners in the system, which is a record, but we have vacancies.

"There is no doubt that, due to capacity issues, the prison system is facing pressure."

Mr Elliott pointed out the government's record on escapees was better than Labor's in 1995 when, he said, 153 prisoners broke out of NSW jails.

The Baird government has promised to build a new 600-bed correctional centre in Grafton by 2019.

It also says 181 new beds will be added to the state's prison system over the coming weeks.

NSW District Court Judge Paul Conlon spoke out on Monday after he was forced to release a man because of prison overcrowding.

The man was facing serious drug charges, but could not receive a mental health assessment at the overcrowded Surry Hills holding cells in Sydney and had to be released, the Daily Telegraph reported.

"Fortunately, as a judge, I'm not in the business of spin, so that means that I can tell it as it is," Judge Conlon told the court.

"If somebody from Corrective Services wants to come into court and tell me that it was possible for (the prisoner) to receive a mental health assessment in the holding cells of Surry Hills, they're welcome in this court and I will apologise to them profusely.

"But that won't happen - because I understand the correctional service system."